Machines that perform work on a site—such as haul trucks, graders, mining trucks, or excavators—typically have combustion engines or other components that may overheat during operation. Overheating may decrease the useful life of the machine's components, damage the components or the machine, and/or result in downtime hurting productivity. To combat overheating, these machines usually have cooling systems that carry heat away from the components susceptible to overheating.
For example, a typical cooling system may circulate a fluid coolant—such as air, oil, or water—through passages of the machine's engine. The coolant may absorb heat from the engine, thereby cooling the engine and preventing it from overheating. The coolant may then pass through a heat exchanger, such as a radiator. A fan pushes or pulls air through channels of the heat exchanger, which removes heat from the coolant so that it can be recirculated to continue cooling the engine.
Cooling systems, however, can sometimes malfunction, causing the overheating-related problems mentioned above. U.S. Pat. No. 8,370,052 to Lin et al. (“the '052 application”) describes an algorithm to diagnose faults in a cooling system. The '052 application's algorithm compares the actual coolant temperature during engine start-up to a predicted coolant temperature that should occur if no cooling system error is present, to identify a cooling system fault condition. If a fault is detected, the algorithm runs the fan and checks whether the coolant temperature changes substantially, which the '052 application contends, allows a thermostat error to be distinguished from a vehicle configuration error.
Although the '052 application's technique may help identify a problem with the cooling system, it may nonetheless be deficient. For example, some types of cooling system faults may not manifest at startup, but at other operating conditions. And while the '052 application algorithm may detect an error with the thermostat, other types of cooling system faults may occur that the algorithm cannot detect.
For example, over time, dirt, dust, and other debris may accumulate within the channels of the heat exchanger, particularly on machines operating in dusty environments like landfills, mines, or excavation sites. The accumulation of debris may degrade the performance of the machine's cooling system, making the machine more likely to overheat. If unchecked for long enough, the channels and/or core of the heat exchanger may become plugged, preventing the ambient air from circulating through the channels and removing heat from the coolant. The debris can eventually harden and become difficult to remove, requiring more costly maintenance or replacement of a heat exchanger that might still have remaining useful life if the plugging had been identified earlier.
This disclosure is directed to overcoming one or more of the problems set forth above and/or other problems with existing systems and methods for monitoring the performance of cooling systems.